After communications hiatus, NASA rover found in standby mode

NASA's Mars rover Opportunity photographed its own tracks as it climbed out of Victoria Crater in this image from 2008. (NASA/JPL-Caltech photo)

NASA’s Opportunity, which has been traversing the Martian surface dutifully since landing in January 2004, has come out of an expected three-week radio silence in self-imposed standby mode.

Opportunity’s mission controllers first figured something with the rover was awry on April 27, when it came back in contact after a planetary alignment called a solar conjunction in which Mars and Earth were on opposite sides of the sun.

Engineers elected to suspend communications rather than risk the sun corrupting commands to Opportunity, another rover called Curiosity or the Mars Reconnaissance Orbiter.

Mission controllers learned Opportunity put itself into standby on April 22 after detecting issues during a routine camera check, according to a statement from NASA.

“Our current suspicion is that Opportunity rebooted its flight software, possibly while the cameras on the mast were imaging the sun," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"We found the rover in a standby state called automode, in which it maintains power balance and communication schedules, but waits for instructions from the ground,” Callas said. “We crafted our solar conjunction plan to be resilient to this kind of rover reset, if it were to occur."

JPL officials said they were hopeful of positive news on May 1 regarding Opportunity, but could not immediately confirm whether the rover was back online.

Opportunity landed on Mars nine years ago with its sister rover, Spirit, to look for signs of water activity on the dry planet. Spirit’s systems failed in 2010, but Opportunity has continued sending back useful information, including plenty of evidence of past water flow.

Curiosity, which touched down last August, received its first programming instructions from ground officials on May 1 after the communications moratorium. Unlike its older relative, Curiosity, which has had its own software hiccups, experienced no issues during the blackout, and officials will now begin to focus on how to guide it through Yellowknife Bay to its eventual destination, a three-mile-high structure called Mount Sharp.

Curiosity already succeeded in its main goal of detecting the necessary ingredients for life, having drilled a rock sample containing hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus and water. It has, however, experienced its fair share of hiccups as well, including a glitch that suspended examination of rock samples on March 16.